How many blocks wide is a Minecraft world?

How to get close to this number

The limit is a computing constraint, not a design choice, and that is the way in. World coordinates are stored in a fixed-size number, and the playable boundary is set where the arithmetic stops behaving. So the answer should be suspiciously close to a round figure in computing terms rather than a round figure in human terms — and it is.

What makes the scale hard to feel is that the game presents it one block at a time. The explanation converts it into two things you can judge: a surface area several times that of the Earth, and a walk from centre to edge measured in hundreds of hours of real play. Converting an abstract limit into a travel time is the most effective way to make a virtual distance mean something.

Worth noting that a world is generated on demand rather than stored, which is why an area larger than a planet fits on a hard drive. Only the chunks a player has visited exist as data; everything else is produced by an algorithm from the world seed when someone arrives. The boundary is therefore a rule about coordinates rather than the edge of anything that has been built.